1. Field of the Invention
One disclosed aspect of the embodiments relates to a photoelectric conversion apparatus, a focus detection apparatus, and an image pickup system.
2. Description of the Related Art
It is known that an image pickup apparatus such as a digital camera and a digital video camera includes a focus detection apparatus. Japanese Patent Laid-Open No. 2011-100077 describes a focus detection apparatus including a photoelectric conversion apparatus having focus detection regions in a vertical direction, a horizontal direction, and a diagonal direction with respect to an image pickup area of an image pickup sensor. However, in Japanese Patent Laid-Open No. 2011-100077, a detailed structure of the photoelectric conversion apparatus is not sufficiently discussed, so that there is a risk that a focal point cannot be accurately detected.